How to protect young and vulnerable trees from the imminent cicada emergence

Bracing for a mass cicada emergence in the next few weeks, tree experts and horticulturists from The Morton Arboretum provided a step-by-step demonstration Tuesday of how people can net their young or unhealthy trees and shrubs.

In early to mid-May, periodical cicadas are due to emerge from the soil in Northern Illinois for the first time in 17 years to spend three to four weeks as adult insects.

An individual cicada lives only three to four weeks, but the appearance of the entire brood can last four to six weeks as the insects don’t all emerge at the same time.

Morton Arboretum plant health care leader Stephanie Adams explained the females “burrow into young tree branches to lay their eggs.”

This can cause the immature tree undue stress and permanent damage.

There is no way to dance around it, arboretum tree experts say. They recommend using a fine mesh fabric called tulle to wrap around young trees for protection.

That’s the same fabric used to make ballerina tutus and is available at most craft stores.

Experts urge to look for netting that has holes no bigger than a quarter inch across. Any bigger and the insect can climb through, which defeats the purpose.

The fabric lets moisture in and out and allows sunlight to penetrate to reach the tree or plant when needed, they say.

“The reason we are using tulle is because we know that physical barriers work. We know that if you put this barrier on the tree or the woody plant, it will be effective,” said Plant Clinic Manager Spencer Campbell.

Cicadas emerge every year in the eastern United States, at either 13-year or 17-year intervals. This year is notable because two broods are emerging simultaneously for the first time in 221 years.

There will be millions of these native insects, particularly in areas with lots of mature trees, and their mating calls, performed by the males, will be loud.

These periodical cicadas are harmless to humans and pets. They cannot sting, bite or pinch. They are part of the natural ecosystem and benefit it through their activities in the soil. Their digging helps irrigate the soil, which contributes to soil health. After their brief life cycle, their bodies will decompose putting nutrients and minerals back into the soil, experts say.